Method of manufacturing a non-aqueous electrolyte secondary battery by subjecting sodium magnesium metal oxide to ion-exchange of sodium for lithium

Abstract

A method of manufacturing a non-aqueous electrolyte secondary battery by subjecting a sodium-magnesium-containing oxide represented by the general formula Na c Mg b MO 2±a , where 0.65≦c≦0.75, 0<b≦0.3, 0≦a≦03, and M is at least one of manganese and cobalt, to ion-exchange of sodium for lithium by using a molten salt, an aqueous solution, or an organic solvent, to prepare a positive electrode active material.

1. A method of manufacturing a non-aqueous electrolyte secondary battery, comprising:
 subjecting a sodium-magnesium-containing oxide represented by the general formula Na c Mg b MO 2±α , where 0.65≦c≦0.75, 0<b≦0.3, 0≦α≦0.3, and M is at least one of manganese and cobalt, to ion-exchange of sodium for lithium by using a molten salt, an aqueous solution, or an organic solvent, to prepare a positive electrode active material; 
 preparing a positive electrode active material slurry containing the positive electrode active material and a binder, and thereafter applying the positive electrode active material slurry to a positive electrode current collector, to prepare a positive electrode; 
 interposing a separator between the positive electrode and a negative electrode to prepare a power-generating element; and 
 encasing the power-generating element in a battery case, and filling an electrolyte solution in the battery case. 
 
     
     
       2. The method according to  claim 1 , wherein the sodium-magnesium-containing oxide is represented by the general formula Na c Mg b Mn x Co y O 2±α  where 0.65≦c≦0.75, 0<b≦0.3, 0.45≦x≦0.55, 0.45≦y≦0.55, 0.90≦x+y≦1.10, and 0≦α≦0.3. 
     
     
       3. The method according to  claim 1 , wherein the positive electrode active material comprises a lithium-containing oxide active material having a crystal structure belonging to an O2 structure, a T2 structure, an O6 structure, or a mixed structure thereof. 
     
     
       4. The method according to  claim 2 , wherein the positive electrode active material comprises a lithium-containing oxide active material having a crystal structure belonging to an O2 structure, a T2 structure, an O6 structure, or a mixed structure thereof. 
     
     
       5. The method according to  claim 1 , wherein 0<b≦0.2. 
     
     
       6. The method according to  claim 2 , wherein 0<b≦0.2. 
     
     
       7. The method according to  claim 3 , wherein 0<b≦0.2. 
     
     
       8. The method according to  claim 4 , wherein 0<b≦0.2.